#include<iostream>
using namespace std;
class Solution {
public:
    int trailingZeroes(int n) {
        int count = 0;
        while(n)
        {
            n /= 5;
            count += n;
        }
        return count;
    }
};
int main()
{
    cout << Solution().trailingZeroes(5);
    return 0;
}